Preheat oven to 450°F. Prepare Pastry for a Single-Crust Pie. On a lightly floured surface, use your hands to slightly flatten pastry. Roll pastry from center to edges into a circle about 12 inches in diameter. Wrap pastry circle around the rolling pin. Unroll into a 9-inch pie plate. Ease pastry into pie plate without stretching it. Trim pastry to 1/2 inch beyond edge of pie plate. Fold under extra pastry even with the plate's edge. Crimp edge as desired. Generously prick bottom and sides of pastry with a fork. Line pastry with a double thickness of foil. Bake for 8 minutes. Remove foil. Bake for 6 to 8 minutes more or until golden. Cool on a wire rack.
Meanwhile, in a medium saucepan combine mascarpone cheese, bittersweet chocolate, and powdered sugar. Cook and stir over medium-low heat until mixture is smooth. Remove from heat; stir in liqueur. Cool to room temperature.
In a chilled medium mixing bowl beat whipping cream with an electric mixer on medium speed until soft peaks form (tips curl). Stir about 1/2 cup of the whipped cream into chocolate mixture to lighten. Fold in the remaining whipped cream just until combined. Spoon chocolate mixture into pastry shell, spreading evenly. Cover and chill for 3 to 24 hours.
To serve, in a medium bowl gently stir together raspberries and melted jam; spoon over chocolate mixture. If desired, garnish with White Chocolate Topping and semisweet chocolate shavings.
Lightly cover pie; store in the refrigerator for up to 24 hours.
In a small heavy saucepan heat and stir white baking chocolate and 1/4 cup whipping cream until chocolate melts and mixture is smooth; cool. In a medium chilled mixing bowl beat 2/3 cup whipping cream with an electric mixer on medium speed until mixture mounds but does not form peaks; turn off mixer. Add white chocolate mixture; beat on low speed just until stiff peaks form (tips stand straight).
In a medium bowl, stir together flour and salt. Using a pastry blender, cut in shortening and butter until pieces are pea size. Sprinkle 1 tablespoon of the ice water over part of the flour mixture; toss gently with a fork. Push moistened dough to side of bowl. Repeat with additional ice water, 1 tablespoon at a time (1/4 to 1/3 cup total), until all of the flour mixture is moistened. Gather mixture into a ball, kneading gently until it holds together.